New obstack_next_free is not an lvalue

New obstack.h casts obstack_next_free to (void *), resulting in it
being a non-lvalue, and warnings on pointer arithmetic.

gcc/
	* gensupport.c (add_mnemonic_string): Make len param a size_t.
	(gen_mnemonic_setattr): Make "size" var a size_t.  Use
	obstack_blank_fast to shrink obstack.  Cast obstack_next_free
	return value.
gcc/objc/
	* objc-encoding.c (encode_aggregate_within): Cast obstack_next_free
	return value.

From-SVN: r229984

gcc/ChangeLog

+2015-11-09  Alan Modra  <amodra@gmail.com>
+
+	* gensupport.c (add_mnemonic_string): Make len param a size_t.
+	(gen_mnemonic_setattr): Make "size" var a size_t.  Use
+	obstack_blank_fast to shrink obstack.  Cast obstack_next_free
+	return value.
+
 2015-11-09  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	PR rtl-optimization/68182

gcc/gensupport.c

@@ -2253,7 +2253,7 @@ htab_eq_string (const void *s1, const void *s2)
    and a permanent heap copy of STR is created.  */
 
 static void
-add_mnemonic_string (htab_t mnemonic_htab, const char *str, int len)
+add_mnemonic_string (htab_t mnemonic_htab, const char *str, size_t len)
 {
   char *new_str;
   void **slot;
@@ -2306,7 +2306,7 @@ gen_mnemonic_setattr (htab_t mnemonic_htab, rtx insn)
   for (i = 0; *cp; )
     {
       const char *ep, *sp;
-      int size = 0;
+      size_t size = 0;
 
       while (ISSPACE (*cp))
 	cp++;
@@ -2333,8 +2333,7 @@ gen_mnemonic_setattr (htab_t mnemonic_htab, rtx insn)
 	    {
 	      /* Don't set a value if there are more than one
 		 instruction in the string.  */
-	      obstack_next_free (&string_obstack) =
-		obstack_next_free (&string_obstack) - size;
+	      obstack_blank_fast (&string_obstack, -size);
 	      size = 0;
 
 	      cp = sp;
@@ -2346,7 +2345,7 @@ gen_mnemonic_setattr (htab_t mnemonic_htab, rtx insn)
 	obstack_1grow (&string_obstack, '*');
       else
 	add_mnemonic_string (mnemonic_htab,
-			     obstack_next_free (&string_obstack) - size,
+			     (char *) obstack_next_free (&string_obstack) - size,
 			     size);
       i++;
     }

gcc/objc/ChangeLog

+2015-11-09  Alan Modra  <amodra@gmail.com>
+
+	* objc-encoding.c (encode_aggregate_within): Cast obstack_next_free
+	return value.
+
 2015-10-29  Andrew MacLeod  <amacleod@redhat.com>
 
 	* objc-lang.c: Reorder #include's and remove duplicates.

gcc/objc/objc-encoding.c

@@ -495,13 +495,14 @@ encode_aggregate_within (tree type, int curtype, int format, int left,
 
   if (flag_next_runtime)
     {
-      if (ob_size > 0  &&  *(obstack_next_free (&util_obstack) - 1) == '^')
+      if (ob_size > 0
+	  && *((char *) obstack_next_free (&util_obstack) - 1) == '^')
 	pointed_to = true;
 
       if ((format == OBJC_ENCODE_INLINE_DEFS || generating_instance_variables)
 	  && (!pointed_to || ob_size - curtype == 1
 	      || (ob_size - curtype == 2
-		  && *(obstack_next_free (&util_obstack) - 2) == 'r')))
+		  && *((char *) obstack_next_free (&util_obstack) - 2) == 'r')))
 	inline_contents = true;
     }
   else
@@ -512,9 +513,10 @@ encode_aggregate_within (tree type, int curtype, int format, int left,
 	 comment above applies: in that case we should avoid encoding
 	 the names of instance variables.
       */
-      char c1 = ob_size > 1 ? *(obstack_next_free (&util_obstack) - 2) : 0;
-      char c0 = ob_size > 0 ? *(obstack_next_free (&util_obstack) - 1) : 0;
+      char c0, c1;
 
+      c1 = ob_size > 1 ? *((char *) obstack_next_free (&util_obstack) - 2) : 0;
+      c0 = ob_size > 0 ? *((char *) obstack_next_free (&util_obstack) - 1) : 0;
       if (c0 == '^' || (c1 == '^' && c0 == 'r'))
 	pointed_to = true;